Towards Efficient Coordination in Multi-Agent Reinforcement Learning through Hybrid Information-Driven Approaches

Abstract: This paper introduces a novel framework to enhance coordination in multi-agent reinforcement learning (MARL) systems by integrating mutual information (MMI) principles with information-driven strategies. Firstly, we propose a variational approach leveraging MMI to promote coordinated behaviors among agents by regulating the cumulative return alongside the simultaneous mutual information between multi-agent actions. Through the introduction of a latent variable inducing nonzero mutual information and the application of a variational bound, a tractable lower bound is derived for the MMI-regularized objective function. This bound combines maximum entropy reinforcement learning with reducing uncertainty in other agents' actions. Subsequently, we present a practical algorithm, Variational Maximum Mutual Information Multi-Agent Actor-Critic (VM3-AC), utilizing policy iteration to maximize the derived lower bound, following a centralized learning with decentralized execution (CTDE) paradigm. Secondly, we explore the challenges of large state spaces and limited computational resources in distributed multi-agent systems, proposing a hybrid information-driven MARL approach. This approach integrates informationtheoretic models as heuristics to aid navigation in sparse state spaces, complemented by information-based rewards within an RL framework to learn higher-level policies efficiently. Our preliminary findings suggest that this hybrid approach could enhance exploration efficiency significantly, demonstrating approximately three orders of magnitude improvement over naive baseline metrics. Although still in its early stages, this work presents a promising direction for future research in achieving efficient coordination in MARL systems